1. Field of the Invention
This invention relates to a rolling bearing of- the type not having any retainer (non-retainer type), and more particularly, to a rolling bearing having a bearing ring of thin wall thickness relative to its outside diameter.
2. Description of the Related Art
A rolling bearing of the type having a thin wall thickness is usually employed when a bearing having a relatively large diameter is required for making, for example, a support for the rotation of any of various kinds of machines. Such a bearing, or more particularly its retainer is, however, insufficient in rigidity.
As a result of rotation, the retainer is deformed and has a lower degree of roundness, and is very likely to make irregular contact with either an inner or an outer ring, become unevenly worn and produce dust of wear.
Such dust exerts an adverse effect on the manufacture of semiconductors, or like devices which have to be manufactured in a clean environment, and no known bearing of the type mentioned above can, therefore, be used in any such environment.
With this invention a non-retainer type rolling bearing which does not have any retainer makes it possible to include a greater number of rolling elements having a smaller distance from one another circumferentially of the bearing.
The smaller spacing between every two adjoining rolling elements, however, makes it likely that they may easily interfere with each other.
There are, thus, likely to occur a number of problems including the wear of the rolling elements, the wear caused on the track surfaces of the rings by the rolling elements sliding thereon, and the rolling motions of the rolling elements at a different speed from one another, resulting in the uneven distribution of the rolling elements, or the fluctuation of torque.
These problems can be improved to some extent or other if it is possible to make a thorough control of various conditions in the manufacture of rolling bearings including the selection of the optimum number and size of the rolling elements. Such a control is, however, very difficult to realize.